{"apiVersion":"1.0","identifier":"CVE-2026-74738","description":"In the Linux kernel, the following vulnerability has been resolved: regmap: sdw-mbq: don-t call an unset readable_reg callback regmap_sdw_mbq_poll_busy() decides whether to poll the Function Busy bit by calling ctx->readable_reg(), which is a straight copy of config->readable_reg. That callback is optional: regmap_readable() treats a NULL ->readable_reg as -every register is readable-, and drivers rely on that. es9356 and tac5xx2-sdw both build an MBQ regmap without one. Since commit ca1b11b36d82 (-regmap: sdw-mbq: Allow defers on undeferrable controls-) the poll runs on every -ENODATA, not only for Controls the driver marked deferrable, so any of those devices answering COMMAND_IGNORED takes the kernel through a NULL function pointer. Treat a missing callback the way the rest of regmap does and poll.","publishedAt":"2026-08-26T15:16:52","lastModifiedAt":"2026-08-26T15:16:52","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-74738","cvssScore":null,"cvssVector":"Pending","epssProbability":0.00173,"riskScore":0,"affectedProduct":"Linux kernel","affectedVersions":"unknown","vulnerabilityType":"Kernel","operatingSystems":[],"links":{"self":"https://www.redsauce.net/api/cves/CVE-2026-74738","webPages":{"es":"https://www.redsauce.net/es/cves/CVE-2026-74738","en":"https://www.redsauce.net/en/cves/CVE-2026-74738","fr":"https://www.redsauce.net/fr/cves/CVE-2026-74738","pt":"https://www.redsauce.net/pt/cves/CVE-2026-74738","de":"https://www.redsauce.net/de/cves/CVE-2026-74738","sk":"https://www.redsauce.net/sk/cves/CVE-2026-74738","el":"https://www.redsauce.net/el/cves/CVE-2026-74738"},"source":"https://nvd.nist.gov/vuln/detail/CVE-2026-74738"}}